Image analysis apparatus, image analysis method, and non-transitory computer readable medium

ABSTRACT

An image analysis apparatus includes an extraction section, an acquisition section, an exclusion section, and a recognition section. The extraction section extracts, from a target image, a text area including a character. The acquisition section acquires a predetermined target-object condition. The predetermined target-object condition defines a target object. The exclusion section searches for the target object in the text area and excludes the target object from a target of character recognition. The text area is extracted by the extraction section. The target object satisfies the predetermined target-object condition. The recognition section performs character recognition on the text area. The text area is an area from which the target object is excluded.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC 119 fromJapanese Patent Application No. 2017-157278 filed Aug. 16, 2017.

BACKGROUND Technical Field

The present invention relates to an image analysis apparatus, an imageanalysis method, and a non-transitory computer readable medium.

SUMMARY

According to an aspect of the invention, there is provided an imageanalysis apparatus including an extraction section, an acquisitionsection, an exclusion section, and a recognition section. The extractionsection extracts, from a target image, a text area including acharacter. The acquisition section acquires a predeterminedtarget-object condition. The predetermined target-object conditiondefines a target object. The exclusion section searches for the targetobject in the text area and excludes the target object from a target ofcharacter recognition. The text area is extracted by the extractionsection. The target object satisfies the predetermined target-objectcondition. The recognition section performs character recognition on thetext area. The text area is an area from which the target object isexcluded.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the present invention will be described indetail based on the following figures, wherein:

FIG. 1 is a front view of an exemplary sheet on which an image that isto be analyzed by an image analysis apparatus according to an exemplaryembodiment is formed;

FIG. 2 is a front view of an exemplary text area according to anexemplary embodiment;

FIG. 3 is a front view of an exemplary result of character recognitionof a text area, according to an exemplary embodiment;

FIG. 4 is a front view of another exemplary text area according to anexemplary embodiment;

FIG. 5 is a front view of exemplary sets of sentences in a text area,according to an exemplary embodiment;

FIG. 6 is a block diagram illustrating a configuration of an imageanalysis system according to an exemplary embodiment;

FIG. 7 is a block diagram illustrating functions of the image analysisapparatus according to first and second exemplary embodiments;

FIG. 8 is a schematic diagram illustrating an exemplary reference imageindicating a target object, according to an exemplary embodiment;

FIG. 9 is a schematic diagram illustrating an exemplary arrangement oflines constituting a target object, according to an exemplaryembodiment;

FIG. 10A is a schematic diagram illustrating another exemplary referenceimage indicating a target object, according to an exemplary embodiment;

FIG. 10B is a schematic diagram illustrating another exemplaryarrangement of lines constituting a target object, according to anexemplary embodiment;

FIG. 11 is a front view of an exemplary text area from which a targetobject is deleted, according to an exemplary embodiment;

FIG. 12A is a schematic diagram illustrating an exemplary area in whicha target object is searched for, according to an exemplary embodiment;

FIG. 12B is a schematic diagram illustrating another exemplary area inwhich a target object is searched for, according to an exemplaryembodiment;

FIG. 12C is a schematic diagram illustrating another exemplary area inwhich a target object is searched for, according to an exemplaryembodiment;

FIG. 13 is a flowchart of an image analysis process according to thefirst exemplary embodiment;

FIG. 14 is a flowchart of an image analysis process according to thesecond exemplary embodiment;

FIG. 15A is a schematic diagram illustrating an example about a heightof a target object, according to an exemplary embodiment;

FIG. 15B is a schematic diagram illustrating another example about theheight of a target object, according to an exemplary embodiment;

FIG. 16 is a front view of an exemplary text area from which a targetobject is deleted, according to an exemplary embodiment;

FIG. 17 is a front view of another exemplary text area from which thelines constituting a target object are deleted, according to anexemplary embodiment;

FIG. 18 is a front view of an example of a text area and a non-textarea, according to an exemplary embodiment;

FIG. 19 is a front view of an exemplary text area from which thenon-text area is separated, according to an exemplary embodiment; and

FIG. 20 is a flowchart of an image analysis process according to a thirdexemplary embodiment.

DETAILED DESCRIPTION

Exemplary embodiments of the present invention will be described indetail below by referring to the attached drawings.

First Exemplary Embodiment

An image analyzed by an image analysis apparatus according to a firstexemplary embodiment will be described. FIG. 1 is a front view of anexemplary sheet that is a recording medium on which an image to beanalyzed by the image analysis apparatus according to the firstexemplary embodiment is formed.

For example, as illustrated in FIG. 1, a line 30 for defining an entireimage is drawn on a sheet P on which an image (for example, a designdrawing) to be analyzed by the image analysis apparatus is drawn. In thefirst exemplary embodiment, the case in which the line 30 for definingthe entire image is a rectangular figure frame will be described.

In the first exemplary embodiment, for example, the case in which, asillustrated in FIG. 1, text areas 32A and 32B that are areas includingcharacters, a table area 34 that is an area including a table, an imagearea 36 that is an area including an image, and the like are arrangedinside the line 30 for defining the entire target image will bedescribed.

For example, as illustrated in FIG. 2, a text 40 in which “text” isarranged in the first line and in which “correct the second line” isarranged in the second line is described in the text area 32A. In thetext area 32A, for example, a character, a symbol, or a figure(hereinafter referred to as a “target object”) 42 which is not relatedto the text included in the image may be also described so as to beadjacent to the text 40 on the left side, that is, in the X direction,and so as to extend across the first and second lines.

In the first exemplary embodiment, the case in which the target object42 has a triangular frame will be described. However, this is notlimiting. The target object 42 may have, for example, a circular,elliptical, rectangular, or polygonal frame. The target object 42 mayhave no frames, and may be a symbol itself, such as a numeric character,an alphabet character, or a mark.

Examples of the type of the target object 42 include a symbol about arevision matter, a symbol indicating a geometrical tolerance for a shapeor the like, a symbol indicating surface roughness, and a symbolindicating a caution-needed area.

The texts described in the text areas 32A and 32B are recognized byperforming known character recognition processing. For example, asillustrated in FIG. 2, in the case where the target object 42 as well asthe text 40 is described in the text area 32A, in character recognitionof the text area 32A, the target object 42 may be falsely recognized asbeing a part of the text 40. In this case, the above-described two-linedescription of “text” and “correct the second line” may be falselyrecognized to be a one-line description. Thus, for example, asillustrated in FIG. 3, a text area 44 which is a result of characterrecognition of the text area 32A and in which “Δ oe second line” isdescribed may be obtained through false recognition.

For example, as illustrated in FIG. 4, assume that a text 48 isdescribed in a text area 46. In the text 48, “laser print surface” isarranged in the first line, “See the artwork No. X.” is arranged in thesecond line, and “Select a typeface and a position according to theartwork.” is arranged in the third line. In addition, assume that atarget object 50 having a height (the length in the Y direction) equalto that of two lines of the text 48 is described on the right side ofthe text 48 so as to extend across the first and second lines of thetext 48.

In this case, for example, as illustrated in FIG. 5, the first andsecond lines of the text 48 and the target object 50 in the text area 46may be recognized to be a single text (one-line text) 48A, and the thirdline of the text 48 may be recognized to be a single text (one-linetext) 48B.

The image analysis apparatus according to the first exemplary embodimentextracts, from a target image, a text area which is an area includingcharacters, and obtains a predetermined target-object condition. Theimage analysis apparatus searches, in the extracted text area, for atarget object satisfying the predetermined target-object condition,excludes the searched target object from the target of characterrecognition, and recognizes characters in the text area from which thetarget object has been excluded. The predetermined target-objectcondition will be described below.

The configuration of an image analysis system and the functions of theimage analysis apparatus according to the first exemplary embodimentwill be described. FIG. 6 is a block diagram illustrating theconfiguration of an image analysis system 10 according to the firstexemplary embodiment. FIG. 7 is a block diagram illustrating thefunctions of an image analysis apparatus 12 according to the firstexemplary embodiment.

As illustrated in FIG. 6, the image analysis system 10 includes theimage analysis apparatus 12 and an image reading apparatus 14. The imagereading apparatus 14 which is a so-called scanner reads a drawing madeon a sheet P, generates color image data or monochrome image data, andoutputs the generated image data to the image analysis apparatus 12. Asillustrated in FIG. 7, the image analysis apparatus 12 includesfunctional units, that is, an extraction unit 20, an acquisition unit22, an exclusion unit 24, and a recognition unit 26.

In terms of the hardware configuration of the image analysis apparatus12, the image analysis apparatus 12 according to the first exemplaryembodiment is implemented through a central processing unit (CPU)controlling the operations of the entire apparatus. That is, the imageanalysis apparatus 12 includes the CPU, a read only memory (ROM) havingstored therein, for example, various programs and various parameters inadvance, and a random access memory (RAM) used, for example, as a workarea in the CPU's execution of various programs, and a storage unitincluding a nonvolatile memory such as a flash memory.

The image analysis apparatus 12 includes a communication line interface(I/F) unit receiving/transmitting communication information from/toexternal apparatuses. The image analysis apparatus 12 also includes anoperation display unit which receives user instructions for the imageanalysis apparatus 12, and which notifies the user of variousinformation, for example, about the operational condition of the imageanalysis apparatus 12. The operation display unit includes, for example,a display for displaying data, and a keyboard and mouse for inputtingdata. However, the operation display unit is not limited to this, andmay include, for example, a touch-panel display and hardware keys, suchas a numeric keypad and a start button. On the touch-panel display,various information and display buttons for receiving operationinstructions through execution of programs are displayed.

The extraction unit 20 receives image data from the image readingapparatus 14, and obtains a read image indicated by the received imagedata, as an image (hereinafter referred to as a “target image”) which isthe target of character recognition. In the first exemplary embodiment,the case in which the extraction unit 20 receives image data from theimage reading apparatus 14 will be described. However, this is notlimiting. The image data may be received through the communication lineI/F unit from an external apparatus. When image data is stored in thestorage unit, the image data may be read from the storage unit.

The extraction unit 20 performs layout analysis on the obtained targetimage so as to extract text areas included in the target image. In thefirst exemplary embodiment, to avoid a complicated description, the casein which the target image is obtained by reading, as monochrome imagedata, a sheet P on which a drawing is made in black with a whitebackground will be described. The extraction unit 20 is an exemplaryextraction section.

The extraction unit 20 divides the target image into multiple areasthrough layout analysis. In this example, the case in which projectionis used as an exemplary method of dividing a target image into multipleareas through layout analysis will be described.

That is, the target image is projected in a predetermined firstdirection (for example, the direction parallel to the X axis). Thus, inthe histogram (projected distribution) of the black pixels in the targetimage, there appear upper peaks corresponding to portions having a largenumber of black pixels and lower peaks corresponding to portions havinga small number of black pixels. When a lower peak portion among theupper and lower peaks satisfies a determination condition fordetermining a portion at which an area is to be divided, the area isdivided in the projection direction. Similarly, the target image isprojected in the direction crossing the first direction (for example,the direction parallel to the Y axis). When a lower peak portion amongthe upper and lower peaks of the histogram of the black pixels in thetarget image satisfies the determination condition, the area is dividedin the projection direction. The division operation in the twodirections is recursively performed so that the target image is dividedinto multiple divided areas.

The extraction unit 20 then discriminates the type of informationdescribed in each divided area, on the basis of the components (objects)included in the divided area. The types include a text, a table, and animage. In the example illustrated in FIG. 1, on the basis of thediscriminated types, four areas, that is, the text areas 32A and 32Bcorresponding to texts, the table area 34 corresponding to a table, andthe image area 36 corresponding to an image, are discriminated.

The extraction unit 20 then extracts text areas from the discriminatedareas. In the example in FIG. 1, two areas, that is, the text area 32Aand the text area 32B, are extracted from the four areas.

For example, the acquisition unit 22 reads data which indicates apredetermined target-object condition and which is stored in the storageunit. Thus, the acquisition unit 22 obtains the predeterminedtarget-object condition. The predetermined target-object condition is acondition serving as a reference for determining whether or not, forexample, a character, a symbol, or a figure included in a text area is atarget object. Examples of the predetermined target-object conditioninclude a condition based on a reference image indicating each targetobject, a condition based on the arrangement of the lines constitutingeach target object, and a condition about the height and the like ofeach target object, which are described below. The acquisition unit 22is an exemplary acquisition section.

The exclusion unit 24 searches, in a text area extracted by theextraction unit 20, for a target object satisfying the predeterminedtarget-object condition obtained by the acquisition unit 22. Theexclusion unit 24 excludes the searched target object from the target ofcharacter recognition performed by the recognition unit 26. Theexclusion unit 24 is an exemplary exclusion section.

In the first exemplary embodiment, the case in which one of method (1)and method (2) is used as an exemplary method of searching for a targetobject will be described.

(1) A method in which reference images indicating the target objectsthat are to be excluded are obtained as the predetermined target-objectcondition, and in which, for example, a character, a symbol, or a figuresimilar to one of the obtained reference images is searched for.

(2) A method in which data indicating the arrangements of the linesconstituting the target objects that are to be excluded is obtained asthe predetermined target-object condition, and in which, for example, acharacter, a symbol, or a figure similar to one of the line arrangementsindicated by the obtained data is searched for.

The case in which the method (1) is used to search for a target objectwill be described.

The acquisition unit 22 obtains a reference image 52 indicating a targetobject that is to be excluded, as the predetermined target-objectcondition. For example, when the acquisition unit 22 is to exclude atriangular symbol such as the target object 42 illustrated in FIG. 2,for example, the acquisition unit 22 obtains the reference image 52indicating a triangular symbol as illustrated in FIG. 8.

The exclusion unit 24 extracts a character candidate area correspondingto a character, a symbol, a figure, or the like from the text area, forexample, through binarization or labeling. The exclusion unit 24calculates the similarity between the extracted character candidate areaand the reference image 52. Examples of a method of calculating asimilarity include the sum of absolute difference (SAD) and thezero-means normalized cross-correlation (ZNCC) which are similarityindexes that are typically used in pattern matching techniques. Anothermethod of calculating a similarity is, for example, a method in whicheach area to be subjected to calculation is divided into multiple areas(for example, multiple 5×5 grid areas); a similarity of each dividedarea is calculated, for example, on the basis of the presence of a line,the length of the line, and the orientation of the line in the dividedarea; and the calculated similarities are added together.

Examples of the orientation of a line include a horizontal-directionline (a line parallel to the X direction), a vertical-direction line (aline parallel to the Y direction), a slanting line extending from lowerleft to upper right (a line such that, as the X-direction value isincreased, the Y-direction value is increased), and a slanting lineextending from upper left to lower right (a line such that, as theX-direction value is increased, the Y-direction value is decreased).However, any known method which is typically used may be used as amethod of calculating a similarity.

At that time, at least one of the extracted character candidate area andthe reference image 52 may be enlarged or reduced so that the size ofthe extracted area and the size of the reference image 52 are equal toeach other or so that the extracted area and the reference image 52 areeasily compared with each other.

When the calculated similarity is equal to or more than a threshold, theexclusion unit 24 determines, for example, a character, a symbol, or afigure described in the extracted area, to be the target object, andexcludes, for example, the character, the symbol, or the figure from thetarget of character recognition performed by the recognition unit 26.

The case in which a target object is searched for by using the method(2) will be described.

The acquisition unit 22 obtains data indicating the arrangement of thelines constituting a target object that is to be excluded, as thepredetermined target-object condition. For example, when a triangularsymbol such as the target object 42 illustrated in FIG. 1 is to beexcluded, the acquisition unit 22 obtains data indicating thearrangement of the three lines constituting a triangle, for example, asillustrated in FIG. 9. In the example in FIG. 9, data indicating thatthree lines (a) to (c) described below are arranged is obtained. Thus,only components included in the target image are used to search for atarget object.

(a) A slanting line 54A extending from lower left to upper right isarranged in a left area in an area for calculating a similarity.

(b) A slanting line 54B extending from upper left to lower right isarranged in a right area in the area for calculating a similarity.

(c) A line 54C extending in the horizontal direction is arranged in alower area in the area for calculating a similarity.

The exclusion unit 24 extracts a character candidate area correspondingto a character, a symbol, a figure, or the like from a text area, forexample, through binarization or labeling. In addition, the exclusionunit 24 calculates a similarity between the arrangement of the linesincluded in the extracted character candidate area and the arrangementof the lines constituting the target object that is to be excluded. Themethod of calculating a similarity may be a known method which istypically used. In addition, when the calculated similarity is equal toor more than a threshold, the exclusion unit 24 determines the symbol orthe character described in the extracted area, to be the target object,and excludes the symbol or the character from the target of characterrecognition performed by the recognition unit 26.

In the first exemplary embodiment, the case of a triangular targetobject is described. However, the shape of a target object is notlimited to this. For example, in the case where a pentangular symbol isto be excluded and where the method (1) is used, for example, areference image 56, as illustrated in FIG. 10A, indicating a pentangularsymbol is obtained. For example, in the case where a pentangular symbolis to be excluded and where the method (2) is used, for example, data,as illustrated in FIG. 10B, indicating that five lines (d) to (h)described below are arranged is obtained.

(d) A line 58A extending in the vertical direction is arranged in a leftarea in an area for calculating a similarity.

(e) A line 58B extending in the horizontal direction is arranged in anupper area in the area for calculating a similarity.

(f) A line 58C extending in the horizontal direction is arranged in alower area in the area for calculating a similarity.

(g) A slanting line 58D extending from upper left to lower right isarranged in an upper right area in the area for calculating asimilarity.

(h) A slanting line 58E extending from lower left to upper right isarranged in a lower right area in the area for calculating a similarity.

For example, as illustrated in FIG. 11, the exclusion unit 24 deletesthe target object 42 from the text area 32A. Thus, the exclusion unit 24excludes the target object 42 from the target of character recognitionperformed by the recognition unit 26. Accordingly, in characterrecognition of the text area 32A, the text 40 in the text area 32A issubjected to character recognition.

In the first exemplary embodiment, the case where, in the entire textarea, a target object satisfying the predetermined target-objectcondition which is obtained by the acquisition unit 22 is searched forand where the searched target object is excluded from the target ofcharacter recognition performed by the recognition unit 26 is described.However, this is not limiting. In a search area which is a portion ofthe text area, a target object satisfying the predeterminedtarget-object condition obtained by the acquisition unit 22 may besearched for, and the searched target object may be excluded from thetarget of character recognition performed by the recognition unit 26.

In the first exemplary embodiment, the search area is an area, in thetext area, in which it is predicted that a target object is included.For example, a target object such as a symbol about a revision matter isoften arranged in an end area including the right end or in an end areaincluding the left end in the text area, for example, as illustrated inFIGS. 2 and 4.

Therefore, for example, as illustrated in FIG. 12A, in an end area 60(an area indicated by using dots in FIG. 12A) which is a portion of thetext area and which includes a left end 60A of the text area 32A, atarget object satisfying the predetermined target-object conditionobtained by the acquisition unit 22 may be searched for. The end area 60is an exemplary search area.

Alternatively, for example, as illustrated in FIG. 12B, in an end area62 (an area indicated by using dots in FIG. 12B) which is a portion ofthe text area and which includes a right end 62A of the text area 46, atarget object satisfying the predetermined target-object conditionobtained by the acquisition unit 22 may be searched for. The end area 62is an exemplary search area. The search area is not limited to the endarea 62 illustrated in FIG. 12B. Searching may be performed in the rightend of one-line texts described in the text area 46.

Alternatively, for example, as illustrated in FIG. 12C, in an outlinearea 66 (an area indicated by using dots in FIG. 12C) which is a portionof the text area and which includes the outline 66A of the text area 64,a target object satisfying the predetermined target-object conditionobtained by the acquisition unit 22 may be searched for. The outlinearea 66 is an exemplary search area.

Further, a target object may be searched for by determining whether ornot at least one of the following objects satisfies the predeterminedtarget-object condition: an object, such as a character, a symbol, or afigure positioned on the rightmost area of the text area; and an object,such as a character, a symbol, or a figure positioned on the leftmostarea of the text area. In this case, it is determined that, for example,a character, a symbol, or a figure determined to be closest to an end ofthe text area and to satisfy the predetermined target-object conditionis determined to be a target object. Thus, regardless of an area, suchas an end area or an outline area in the text area, a target object issearched for on the basis of the arrangement of, for example, acharacter, a symbol, or a figure in the text area.

When the exclusion unit 24 excludes target objects, the recognition unit26 performs character recognition on the text areas from which thetarget objects have been excluded by the exclusion unit 24. In the casewhere a target object is not found in the text area and where theexclusion unit 24 does not exclude a target object, the recognition unit26 performs character recognition on the text area extracted by theextraction unit 20. The recognition unit 26 is an exemplary recognitionsection.

The flow of an image analysis process performed by the image analysisapparatus 12 according to the first exemplary embodiment when apredetermined execution instruction is given will be described byreferring to the flowchart in FIG. 13. In the first exemplaryembodiment, the programs for the image analysis process are stored inadvance in the storage unit. However, this is not limiting. For example,the programs for the image analysis process may be received from anexternal apparatus through the communication line I/F unit and may bestored in the storage unit. Alternatively, the programs for the imageanalysis process which are recorded in a recording medium such as acompact disc-read-only memory (CD-ROM) may be read through a CD-ROMdrive or the like so that the image analysis process is performed.

In step S101, the extraction unit 20 receives image data from the imagereading apparatus 14 so as to obtain a target image.

In step S103, the extraction unit 20 performs layout analysis on thereceived target image so as to extract text areas in the target image.

In step S105, the acquisition unit 22 acquires the predeterminedtarget-object condition.

In step S107, the exclusion unit 24 searches, in an extracted text area,for target objects satisfying the obtained predetermined target-objectcondition.

In step S109, the exclusion unit 24 determines whether or not targetobjects have been obtained through the searching in the extracted textarea. If the exclusion unit 24 determines that target objects have beenobtained through the searching in step S109 (Y in S109), the processproceeds to step S111. If the exclusion unit 24 determines that notarget objects have been obtained through the searching in step S109 (Nin S109), the process proceeds to step S113.

In step S111, the exclusion unit 24 excludes the searched target objectsfrom the target of character recognition.

In step S113, the recognition unit 26 performs character recognition onthe text area from which the target objects have been excluded.

In step S115, the recognition unit 26 stores information about therecognized characters, as recognition information in the storage unit.

In step S117, the extraction unit 20 determines whether or not a nexttarget image is present. If the extraction unit 20 determines that anext target image is present in step S117 (Y in S117), the processproceeds to step S101, and the processes in steps S101 to S117 areperformed on the next target image. If the extraction unit 20 determinesthat a next target image is not present (N in S117), execution of theprograms for the image analysis process is ended.

Thus, in the first exemplary embodiment, text areas which are areasincluding characters are extracted from a target image, and thepredetermined target-object condition is obtained. In the extracted textareas, target objects satisfying the predetermined target-objectcondition are searched for. The target objects are excluded from thetarget of character recognition. Character recognition is performed onthe text areas from which the target objects have been excluded. Inexclusion of target objects from the target of character recognition,the searched target objects are deleted from the text areas, andcharacter recognition is performed on the text areas from which thetarget objects have been deleted.

In the first exemplary embodiment, the case in which a target objectsatisfying the predetermined target-object condition is searched for isdescribed. However, this is not limiting. A target-object arrangementcondition about an area in which a target object is arranged in a textarea may be obtained. A target object of which the arrangement area inthe text area satisfies the target-object arrangement condition may beexcluded from the target of character recognition. Examples of thetarget-object arrangement condition include a state in which the targetobject is arranged in the outline area 66 including the outline of thetext area, and the state in which the target object is arranged in theend area 60 or 62 including an end of the text area.

Second Exemplary Embodiment

An image analysis apparatus according to a second exemplary embodimentwill be described.

In the first exemplary embodiment, the case in which, by deleting alltarget objects in a text area, the target objects are excluded from thetarget of character recognition performed by the recognition unit 26 isdescribed. In contrast, in the second exemplary embodiment, the case inwhich only target objects satisfying a condition about one of theheight, the size, and the position (hereinafter referred to as a“condition about the height and the like”) are deleted among the targetobjects in a text area, and in which the target objects are thus deletedfrom the target of character recognition performed by the recognitionunit 26 will be described.

The configuration of the image analysis apparatus according to thesecond exemplary embodiment is the same as that of the image analysisapparatus 12 according to the first exemplary embodiment, and theconfiguration of the components will not be described.

The flow of the image analysis process performed by the image analysisapparatus 12 according to the second exemplary embodiment when apredetermined execution instruction is given will be described byreferring to the flowchart in FIG. 14. In the second exemplaryembodiment, the programs for the image analysis process are stored inadvance in the storage unit. However, this is not limiting. For example,the programs for the image analysis process may be received from anexternal apparatus through the communication line I/F unit, and may bestored in the storage unit. Alternatively, the programs for the imageanalysis process which are recorded in a recording medium such as aCD-ROM may be read through a CD-ROM drive or the like so that the imageanalysis process is performed.

In steps S101 to S103, similar processes to steps S101 to S103 in thefirst exemplary embodiment are performed.

In step S105, the acquisition unit 22 acquires the predeterminedtarget-object condition. At that time, the acquisition unit 22 acquiresthe reference image 52, which indicates a target object that is to beexcluded, or the arrangement of the lines constituting a target objectthat is to be excluded. In addition, the acquisition unit 22 acquiresthe condition about the height and the like. The height of a targetobject indicates the Y-direction length of the target object. The sizeof a target object indicates the size of the target object based on atleast one of the X-direction length and the Y-direction length of thetarget object. The position of a target object indicates the position ofthe target object in the XY coordinates.

The condition about the height and the like indicates a predefinedcondition stipulating a target object's height, size, and position whichdo not hinder character recognition of a text in a text area. In thesecond exemplary embodiment, for example, the condition about the heightin the condition about the height and the like indicates that the heightof a target object is larger than the height of a character which is thetarget of character recognition. The condition about the size in thecondition about the height and the like indicates that the size of atarget object is larger than the size of a character which is the targetof character recognition. The condition about the position in thecondition about the height and the like indicates that the Y-directionposition of a target object is located in a space between lines of atext in the text area. The expression “located in a space between lines”indicates that the range of the height-direction (Y-direction) positionof a target object extends across multiple lines. In addition, theheight or the size of a character that is the target of characterrecognition may be stored in the storage unit in advance, or may becalculated on the basis of the height or the size of, for example, theextracted character, symbol, or figure.

In consideration of an error in character recognition, the conditionabout the height may indicate that the height of the target object 42 islarger than the maximum height, which includes the value of an error, ofa character which is the target of recognition. Alternatively, thecondition about the height may indicate that the height of the targetobject 42 is larger than a value with which it has been confirmed thatfalse recognition does not occur in character recognition.

Similarly, in consideration of an error in character recognition, thecondition about the size may indicate that the size of the target object42 is larger than the maximum size, which includes the value of anerror, of a character which is the target of recognition. Alternatively,the condition about the size may indicate that the size of the targetobject 42 is larger than a value with which it has been confirmed thatfalse recognition does not occur in character recognition.

Similarly, in consideration of an error in character recognition, thecondition about the position may indicate that the range of theheight-direction position of the target object 42 extends across a spacebetween character lines which are the target of recognition. Theheight-direction (Y-direction) length of a space between character linesis set to the average, the median, the mode, or the minimum of thelengths of spaces between character lines which are the target ofrecognition. Alternatively, an additional condition that the range ofthe height-direction position of the target object 42 is larger than theaverage, the median, the mode, or the minimum of spaces betweencharacter lines which are the target of recognition may be added to thecondition about the position. Alternatively, the condition about theposition may indicate that the range of the height-direction position ofthe target object 42 falls within the range of the position in which ithas been confirmed that false recognition does not occur in characterrecognition.

In steps S107 to S111, similar processes to steps S107 to S111 in thefirst exemplary embodiment are performed.

For example, as illustrated in FIG. 15A, when the height ‘a’ of thetarget object 42 in the text area 32A is larger than the maximum height‘b’ of a character of the text 40 which is the target of recognition,the target object 42 satisfies the condition about the height and thelike. Therefore, it is determined that the target object 42 has beenfound through the searching in the extracted text area 32A.

For example, as illustrated in FIG. 15B, when the height ‘c’ of a targetobject 72 in a text area 70 is not larger than the maximum height ‘d’ ofa character of a text 71 which is the target of recognition, the targetobject 72 does not satisfy the condition about the height and the like.Therefore, when other extracted target objects similarly do not satisfythe condition about the height and the like, it is determined that notarget objects have been found through the searching in the extractedtext area 70.

In deletion of the target object 72 from the text area 70, for example,the target object 72 is deleted as illustrated in FIG. 16. Thus, thetarget object 72 is excluded from the target of character recognitionperformed by the recognition unit 26.

When the target object 72 is searched for on the basis of thearrangement of the lines constituting the target object 72 (when themethod (2) is used), for example, only the lines constituting the targetobject 72 may be deleted as illustrated in FIG. 17. In this case, thecharacter “3” described inside the lines constituting the target object72 is not deleted. The character “3” is included in the target ofcharacter recognition performed by the recognition unit 26.

In steps S113 to S117, similar processes to steps S113 to S117 in thefirst exemplary embodiment are performed.

Thus, in the second exemplary embodiment, text areas which are areasincluding characters are extracted from the target image, and thepredetermined target-object condition is obtained. In addition, in theextracted text areas, target objects satisfying the predeterminedtarget-object condition are searched for. Among the found targetobjects, target objects of which at least one of the height, the size,and the position satisfies the condition about the height and the likeare excluded from the target of character recognition.

In the second exemplary embodiment, the case in which it is determinedwhether or not a target object satisfying the predeterminedtarget-object condition satisfies the condition about the height and thelike is described. However, this is not limiting. It may be determinedwhether or not, for example, a character, a symbol, or a figuredescribed in a text area satisfies the condition about the height andthe like. In this case, regardless of the predetermined target-objectcondition, for example, a character, a symbol, or a figure satisfyingthe condition about the height and the like may be determined to be atarget object, and the target object may be excluded from the target ofcharacter recognition.

Alternatively, it may be determined whether or not, for example, acharacter, a symbol, or a figure satisfying the condition about theheight and the like satisfies the predetermined target-object condition.Then, for example, the character, the symbol, or the figure satisfyingthe predetermined target-object condition may be determined to be atarget object, and the target object may be excluded from the target ofcharacter recognition.

Third Exemplary Embodiment

An image analysis apparatus according to a third exemplary embodimentwill be described.

In the first and second exemplary embodiments, the case in which, bydeleting a target object in a text area, the target object is excludedfrom the target of character recognition performed by the recognitionunit 26 is described. In contrast, in the third exemplary embodiment,the case in which an area corresponding to a target object in a textarea is separated as a non-text area from the text area and in which thetarget object is thus excluded from the target of character recognitionperformed by the recognition unit 26 will be described.

The configuration of the image analysis apparatus 12 according to thethird exemplary embodiment is the same as that of the image analysisapparatus 12 according to the first and second exemplary embodiments,and the configuration of the components will not be described.

In the third exemplary embodiment, the exclusion unit 24 searches, in atext area extracted by the extraction unit 20, for a target objectsatisfying the predetermined target-object condition obtained by theacquisition unit 22. The exclusion unit 24 determines an areacorresponding to a searched target object to be a non-text area, andseparates the non-text area from the text area. Thus, the searchedtarget object is excluded from the target of character recognitionperformed by the recognition unit 26. The exclusion section 24 is alsoan exemplary separation section.

For example, as illustrated in FIG. 18, when the text 40 and the targetobject 42 are described in the text area 32A, the exclusion unit 24recognizes an area 80 corresponding to the text 40 and a non-text area82 corresponding to the target object 42, and separates the non-textarea 82 from the text area 32A. Then, for example, as illustrated inFIG. 19, the exclusion unit 24 uses only the area 80 corresponding tothe text 40, as a text area 84.

The method of searching for a target object by using the exclusion unit24 is similar to the method (1) and the method (2) in the firstexemplary embodiment.

The flow of an image analysis process performed by the image analysisapparatus 12 according to the third exemplary embodiment when thepredetermined execution instruction is given will be described byreferring to the flowchart in FIG. 20. In the third exemplaryembodiment, the programs for the image analysis process are stored inadvance in the storage unit. However, this is not limiting. For example,the programs for the image analysis process may be received from anexternal apparatus through the communication line I/F unit, and may bestored in the storage unit. Alternatively, the programs for the imageanalysis process which are recorded in a recording medium such as aCD-ROM may be read through a CD-ROM drive or the like so that the imageanalysis process is performed.

In steps S201 to S209, similar processes to steps S101 to S109 in thefirst exemplary embodiment (FIG. 13) or the second exemplary embodiment(FIG. 4) are performed.

In step S211, the exclusion unit 24 determines areas corresponding tothe target objects found through the searching, to be non-text areas,and separates the non-text areas from the text areas. Thus, the targetobjects are excluded from the target of character recognition.

In steps S213 to S217, similar processes to steps S113 to S117 in thefirst exemplary embodiment (FIG. 13) or the second exemplary embodiment(FIG. 14) are performed.

Thus, an area corresponding to a target object in a text area isdetermined to be a non-text area, and the non-text area is separatedfrom the text area. Then, character recognition is performed on the textarea from which the non-text area has been separated.

The configuration of the image analysis apparatus 12 (see FIGS. 6 and 7)described in the above-described exemplary embodiments is exemplary.That is, needless to say, unnecessary components may be deleted, or newcomponents may be added without departing from the gist of the presentinvention.

The flows of the processes of various programs described in theabove-described exemplary embodiments (see FIGS. 13, 14, and 20) arealso exemplary. That is, needless to say, deletion of unnecessary steps,addition of new steps, or switching the process order may be performedwithout departing from the gist of the present invention.

The foregoing description of the exemplary embodiments of the presentinvention has been provided for the purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Obviously, many modificationsand variations will be apparent to practitioners skilled in the art. Theembodiments were chosen and described in order to best explain theprinciples of the invention and its practical applications, therebyenabling others skilled in the art to understand the invention forvarious embodiments and with the various modifications as are suited tothe particular use contemplated. It is intended that the scope of theinvention be defined by the following claims and their equivalents.

What is claimed is:
 1. An image analysis apparatus comprising: anextraction section that extracts, from a target image, a text areaincluding a character; an acquisition section that acquires apredetermined target-object condition, the predetermined target-objectcondition defining a target object contained in the extracted text area;an exclusion section that searches for the target object in the textarea and excludes the target object from the text area, the targetobject satisfying the predetermined target-object condition; adetermination section that determines a target of character recognitionto be a remaining portion of the text area after the target object isexcluded therefrom; and a recognition section that performs characterrecognition on the determined target of character recognition.
 2. Theimage analysis apparatus according to claim 1, wherein the exclusionsection deletes the searched target object from the text area; andwherein the determination section determines the target of characterrecognition to be a remaining portion of the text area after the targetobject is deleted therefrom.
 3. The image analysis apparatus accordingto claim 2, wherein the acquisition section acquires an arrangement oflines constituting the target object, and wherein the exclusion sectionsearches for the target object on a basis of the arrangement of thelines constituting the target object, and deletes the lines constitutingthe searched target object.
 4. The image analysis apparatus according toclaim 1, wherein the exclusion section includes a separation sectionthat determines a target-object area to be a non-text area within theextracted text area, and separates the non-text area from the extractedtext area, the target-object area corresponding to the target objectcontained in the extracted text area, and wherein the determinationsection determines the target of character recognition to be a remainingportion of the text area after the non-text area is separated therefrom.5. The image analysis apparatus according to claim 4, wherein theacquisition section acquires an arrangement of lines constituting thetarget object, and wherein the separation section searches for thetarget object by using the arrangement of the lines constituting thetarget object, determines the target-object area to be the non-textarea, and separates the non-text area from the text area, thetarget-object area corresponding to the target object in the text area.6. The image analysis apparatus according to claim 1, wherein theacquisition section acquires a reference image indicating the targetobject, and wherein the exclusion section searches for the target objectby using the reference image, and excludes the target object from thetext area, such that the target object is not included in the determinedtarget of character recognition.
 7. The image analysis apparatusaccording to claim 2, wherein the acquisition section acquires areference image indicating the target object, and wherein the exclusionsection searches for the target object by using the reference image, andexcludes the target object from the extracted text area, such that thetarget object is not included in the determined target of characterrecognition.
 8. The image analysis apparatus according to claim 3,wherein the acquisition section acquires a reference image indicatingthe target object, and wherein the exclusion section searches for thetarget object by using the reference image, and excludes the targetobject from the extracted text area, such that the target object is notincluded in the determined target of character recognition.
 9. The imageanalysis apparatus according to claim 4, wherein the acquisition sectionacquires a reference image indicating the target object, and wherein theexclusion section searches for the target object by using the referenceimage, and excludes the target object from the extracted text area, suchthat the target object is not included in the determined target ofcharacter recognition.
 10. The image analysis apparatus according toclaim 1, wherein the acquisition section acquires a condition about atleast one of a height, a size, and a position of the target object, andwherein the exclusion section excludes the target object from the textarea, such that the target object is not included in the determinedtarget of character recognition, at least one of a height, a size, and aposition of the excluded target object satisfying the condition about atleast one of the height, the size, and the position of the targetobject.
 11. The image analysis apparatus according to claim 1, whereinthe acquisition section acquires a condition about at least one of aheight, a size, and a position of the target object, and wherein theexclusion section searches for and excludes the target object from thetext area, such that the target object is not included in the determinedtarget of character recognition, the excluded target object beingobtained through the searching performed by the exclusion section, atleast one of a height, a size, and a position of the excluded targetobject satisfying the condition about at least one of the height, thesize, and the position of the target object.
 12. The image analysisapparatus according to claim 10, wherein the condition about at leastone of the height, the size, and the position of the target object is atleast one of first to third conditions, the first condition indicatingthat the height of the target object is larger than a height of acharacter that is the target of character recognition performed by therecognition section, the second condition indicating that the size ofthe target object is larger than a size of a character that is thetarget of character recognition performed by the recognition section,and the third condition indicating that a height-direction position ofthe target object is located between lines of a text in the text area.13. The image analysis apparatus according to claim 11, wherein thecondition about at least one of the height, the size, and the positionof the target object is at least one of first to third conditions, thefirst condition indicating that the height of the target object islarger than a height of a character that is the target of characterrecognition performed by the recognition section, the second conditionindicating that the size of the target object is larger than a size of acharacter that is the target of character recognition performed by therecognition section, and the third condition indicating that aheight-direction position of the target object is located between linesof a text in the text area.
 14. The image analysis apparatus accordingto claim 1, wherein the acquisition section acquires a condition aboutan arrangement area, as the predetermined target-object condition, thearrangement area being an area in which the target object is arranged inthe text area, and wherein the exclusion section excludes the targetobject from the text area, such that the target object is not includedin the determined target of character recognition, an arrangement areaof the excluded target object satisfying the condition about thearrangement area.
 15. The image analysis apparatus according to claim 1,wherein the acquisition section acquires a search area, the search areabeing a portion of the extracted text area, and wherein the exclusionsection searches for the target object in the search area.
 16. The imageanalysis apparatus according to claim 15, wherein the search areaincludes an end of the extracted text area.
 17. A non-transitorycomputer readable medium storing a program causing a computer tofunction as the sections of the image analysis apparatus according toclaim
 1. 18. An image analysis method comprising: extracting, from atarget image, a text area including a character; acquiring apredetermined target-object condition, the predetermined target-objectcondition defining a target object contained in the extracted text area;searching for the target object in the extracted text area and excludingthe target object from the text area, the target object satisfying thepredetermined target-object condition; determining a target of characterrecognition to be a remaining portion of the text area after the targetobject is excluded therefrom; and performing character recognition onthe determined target of character recognition.
 19. An image analysisapparatus comprising: an extraction section that extracts, from a targetimage, a text area including a character; an acquisition section thatacquires a predetermined target-object condition, the predeterminedtarget-object condition defining a target object contained in theextracted text area; an exclusion section that searches for the targetobject satisfying the predetermined target-object condition in the textarea and excludes the target object from a target of characterrecognition in the text area, with the proviso that the target objectsatisfies the predetermined target-object condition when at least aheight or a size of the target object is determined to exceed a heightor a size of the character included in the text area; and a recognitionsection that performs character recognition on a remaining portion ofthe text area after the target object is excluded therefrom.